Automatic Detection of Nuclear Spins at Arbitrary Magnetic Fields via Signal-to-Image AI Model.

Quantum sensors leverage matter's quantum properties to enable measurements with unprecedented spatial and spectral resolution. Among these sensors, those utilizing nitrogen-vacancy (NV) centers in diamond offer the distinct advantage of operating at room temperature. Nevertheless, signals received from NV centers are often complex, making interpretation challenging. This is especially relevant in low magnetic field scenarios, where standard approximations for modeling the system fail. Additionally, NV signals feature a prominent noise component. In this Letter, we present a signal-to-image deep learning model capable of automatically inferring the number of nuclear spins surrounding a NV sensor and the hyperfine couplings between the sensor and the nuclear spins. Our model is trained to operate effectively across various magnetic field scenarios, requires no prior knowledge of the involved nuclei, and is designed to handle noisy signals, leading to fast characterization of nuclear environments in real experimental conditions. With detailed numerical simulations, we test the performance of our model in scenarios involving varying numbers of nuclei, achieving an average error of less than 2 kHz in the estimated hyperfine constants.

Effect of composition and coating on the interparticle interactions and magnetic hardness of MFe2O4 (M = Fe, Co, Zn) nanoparticles.

Single domain superparamagnetic ferrite nanoparticles with the composition MFe2O4 (M = Fe, Co, Zn) have been prepared by thermal decomposition of metal acetylacetonates in diphenyl ether or dibenzyl ether, using oleic acid in the presence of oleylamine as a stabilizing agent. The Fe, Co and Zn ferrite nanoparticles are monodisperse with diameters of 4.9, 4.4 and 4.7 nm, respectively. The TG and IR results indicate that four or six carboxylate groups per nm2 are bonded at the surface of the particles acting as chelating and/or bridging bidentate ligands depending on the composition. The oleate groups minimize the interparticle interactions in Fe and Zn ferrite samples, while in the Co ferrite sample dipolar interactions produce broad maxima in the ZFC and energy barriers distribution curves. The inversion degree has been estimated from the Raman spectra and the obtained x values have been used to calculate the saturation magnetization and compare them with the experimental MS values. Compared to bulk materials, the magnetization value is higher for the Zn ferrite sample due to its mixed spinel cation distribution. For the Co ferrite sample, and probably for the Fe one, the low value of saturation magnetization seems to be due to the surface disordered layer of canted spins. Compared to non-coated nanoparticles with the same composition and similar size, the oleate groups, covalently bonded to the superficial cations, increase the anisotropy field and decrease the magnetization.

Nickelocene as precursor of microporous organometallic-derived carbon and nickel oxide-carbon nanocomposite.

Microporous flower-like and spherical carbon particles, made of graphene-like layers, have been obtained via chlorination of nickelocene (Ni(C5H5)2). Their mechanism of formation, in terms of morphology and micro-nanostructure, has been followed from 200 to 900°C. Conventional transmission electron microscopy and high-resolution-TEM observations allow determining that their structure is made of highly disordered graphene-like layers. The Raman spectrum of the high temperature sample exhibits the characteristics D and G bands. The peak positions, the ratio of their intensities (ID/IG) and full width at half maximum suggest a high degree of disorder in the nanostructures. The calculated in-plane correlation length of these graphene-like layers is 1.15nm. In all the carbon particles, electron energy-loss spectroscopy shows sp2 carbon bonding content higher than 95% and mass density in the range of 1.0-1.6g/cm3. Textural studies show Type I adsorption isotherms with surface area of 922m2/g for the sample produced at 900°C. In addition, the basic hydrothermal treatment of the sample chlorinated at 600°C yields a composite material with NiO nanoparticles well dispersed within the carbon matrix.

Multicenter prospective study on the burden of rotavirus gastroenteritis in children less than 3 years of age in Spain.

BACKGROUND: Rotavirus is acknowledged as an important cause of paediatric gastroenteritis worldwide. In Spain, comprehensive data on the burden of rotavirus disease was lacking. METHODS: A prospective, multicenter, observational study was carried out, during the winter season, from October to April 2014 in selected areas of Spain (Catalonia, Basque Country, Andalusia) to estimate the frequency and characteristics of acute gastroenteritis (AGE) and rotavirus gastroenteritis (RVGE) in children ≤3 years of age seeking medical care in primary care and emergency department centres. RESULTS: Of the 1087 episodes of AGE registered, 33.89 % were RVGE positive. The estimated incidence of RVGE, was 40.3 (95 % CI 36.1-44.8) episodes per 10,000 child-months in children ≤ 3 years of age and the 5-month (December-April) seasonal RVGE incidence rate was 2.01 [1.81-2.24] per 100 children. No vaccination and attending a day care centre were the main risk factors for RV infection. RVGE infected children presented more frequently with fever (63.9 % vs. 45.1 %, p = 0.009), vomiting (61.2 % vs. 44.3 %, p = 0.015), suffered more dehydration, and were hospitalised and went to the emergency room more often (41.7 % vs. 15.7 %, p <0.001) than non-RVGE infected ones. Children were usually more tired (77.5 % vs. 54.2 %, p <0.001), tearful, (47.2 % vs. 34.8 %, p <0.001), and easily irritated (76.5 % vs. 59.8 %, p <0.001), and parents were more concerned (41.7 % vs. 15.7 %, p <0.001) and suffered more working rhythm disturbances (39.0 % vs. 22.9 %, p <0.001). The cost for families of RVGE cases was significantly higher than the cost of non-RVGE infected ones (47.3 vs 36.7 euros, p = 0.011). Vaccinated children suffered less clinical symptoms and no hospitalization. Therefore, vaccination decreases the psychosocial stressors caused by the disease in the family. CONCLUSIONS: Rotavirus infections are responsible for a substantial proportion of AGE cases in children ≤3 years of age in Spain attended at primary care visits. RVGE episodes are associated with greater clinical severity, greater alterations in the child´s behaviour, and higher parental distress. The outcomes of the present study recommend that routine rotavirus vaccination in infants ≤3 years of age could considerably reduce the serious burden of this potentially serious childhood disease.

On the origin of the spontaneous formation of nanocavities in hexagonal bronzes (W,V)O3.

Hexagonal (W,V)O3-x oxides of high thermal stability have been synthesized hydrothermally through the intermediate products Nax(W,V)O3·zH2O and (NH4)0.33-x(W,V)O3-y. The obtained crystals show nanostructured surface via the formation of a dense population of polyhedral nanocavities self-distributed along particular crystallographic directions. Nanocavities present a regular size that ranges from 5 to 10 nm in both length and width. The synthesis process involves a significant topotactic relationship between the as-synthesized product and the desired final product and this relationship is suggested as the origin of the observed surface nanostructure. The comparison of our results with observations in different solids has allowed us to suggest that the formation of nanocavities is an extensive spontaneous process when materials are obtained by the chemical reactions of solids leading to products with defined crystallographic orientation with respect to the original compound. The characterization provides evidence regarding the potential relevance of nanocavities in the functional properties of the resulting solids.

Chlorination and solvothermal treatment of Zr(C5H5)2Cl2: a synthetic combination to produce nanometric tetragonal ZrO2.

A novel synthetic strategy based on the combination of the chlorination of an organometallic precursor followed by solvothermal treatment is found to be successful in the synthesis of tetragonal nano-ZrO(2) or nano-ZrO(2), embedded in an amorphous carbon matrix, depending on the solvent employed in the solvothermal step. The chemical and structural features (chemical composition, size and surface defects) of the intermediate and final materials have been determined experimentally mainly by high resolution transmission electron microscopy, electron energy loss spectroscopy, and Z-contrast images. These local techniques reveal that the nanoparticles consist of tetragonal ZrO(2) with an average size of 1.7 ± 0.4 and 6.2 ± 0.9 nm for the embedded in carbon and the free nano-ZrO(2), respectively.

Reduction in pediatric invasive pneumococcal disease in the Basque Country and Navarre, Spain, after introduction of the heptavalent pneumococcal conjugate vaccine.

This study evaluated the incidence of invasive pneumococcal disease, identified the causal serotypes, and tracked the evolution of the antibiotic susceptibility of Streptococcus pneumoniae isolates in the regions of the Basque Country and Navarre, Spain, before and after the introduction of the heptavalent pneumococcal conjugate vaccine. The study included all children aged between birth and 5 years diagnosed with bacteremia, meningitis, or bacteremic pneumonia caused by pneumococci. By the second year after introduction of the heptavalent pneumococcal conjugate vaccine, compared with the period 1998-2001, the incidence of invasive disease decreased by 64.3% in children less than 12 months of age, by 39.7% in children less than 24 months of age, and by 37.5% in children less than 60 months of age. The prevalence of clinical isolates of S. pneumoniae that lacked susceptibility to penicillin decreased by 58.2% among children less than 60 months of age. With an estimated coverage by four-dose heptavalent pneumococcal conjugate vaccine of 28-45% in 2003, the number of invasive pneumococcal infections in the Basque Country and in Navarre fell significantly after just 2 years of immunization, underscoring the importance of improving vaccination coverage under a universal childhood immunization program.

Interferon alpha treatment of chronic hepatitis C in HIV-infected patients receiving zidovudine: efficacy, tolerance and response related factors.

BACKGROUND/AIMS: In our area most of the human immunodeficiency virus (HIV) infected patients are intravenous drug users; HIV and hepatitis C virus infections often coexist in these patients. Due to the repercussions of both infections, we designed a trial to evaluate the efficacy, response-related factors and tolerance during an eight-month regime of recombinant interferon alpha-2b on hepatitis C virus infection. METHODOLOGY: We included 79 patients in an open, prospective and multicentric trial with zidovudine and interferon alpha-2b. Response to interferon treatment was evaluated by biochemical and histopathological criteria. RESULTS: A complete response (alanine aminotransferase normalization) was obtained in 57.4% of patients. The significant response-related factors were: degree of histopathological activity, CD4+ cell number and initial leukocyte number. CONCLUSIONS: Recombinant interferon therapy seems to be effective for chronic hepatitis C in HIV infected patients; the best response was in those with active chronic hepatitis and CD4+ cell counts > or = 200/mm3. General tolerance was variable, although side effects were not different from those seen in non-HIV patients. The most common side effect was flu-like syndrome (constitutional manifestations), with no interference on treatment continuity; however, hematological toxicity prevents the indiscriminate use of interferon.

Assessment of the immunogenicity and reactogenicity of a quadrivalent diphtheria, tetanus, acellular pertussis and hepatitis B (DTPa-HBV) vaccine administered in a single injection with Haemophilus influenzae type b conjugate vaccine, to infants at 2, 4 and 6 months of age.

This double-blind, randomised study was performed to assess the immunogenicity and reactogenicity of three lots of a quadrivalent diphtheria-tetanus-acellular pertussis-hepatitis B vaccine (DTPa-HBV) co-administered with three lots of Haemophilus influenzae type b conjugate (Hib) vaccine in one injection, as a primary vaccination course in healthy infants at 2, 4 and 6 months of age. 269 infants (8-11 weeks of age) were randomly allocated to three groups to receive DTPa-HBV/Hib vaccines, concomitantly with oral polio vaccine. Blood samples for antibody determinations were taken before vaccination and 1 month after the third dose in 262 subjects. Local and general symptoms were recorded by parents on diary cards. All vaccinees had post-vaccination protective anti-D and anti-T (> or = 0.1 IU ml-1) antibodies, and 98% had protective anti-HBs antibody titres (> or = 10 mIU ml-1). There were no statistically significant differences between groups in post-vaccination anti-D, anti-T, anti-HBs antibody geometric mean titres (GMT), these being 3.49 IU ml-1, 5.92 IU ml-1 and 1109 mIU ml-1, respectively. All subjects responded to three pertussis components, i.e. pertussis toxin (PT), filamentous haemagglutinin (FHA) and pertactin (PRN). Although statistically significant differences in GMTs of anti-PT, anti-FHA and anti-PRN were found between groups, these were not believed to be of any clinical relevance as the minimum GMTs were 60, 193 and 230 EL.U ml-1 for anti-PT, anti-FHA and anti-PRN, respectively. There were no statistically significant differences in anti-PRP antibody GMT (4.05 micrograms ml-1) between groups, 100% and 85% of subjects having titres > or = 0.15 and 1.0 microgram ml-1, respectively. No symptoms were reported for one third of the subjects. Fever (> 38 degrees C) was reported after 16% of doses, with < 1% having > 39.5 degrees C. Almost all local and general symptoms were mild or moderate, and lasted less than 48 h. No subject dropped out due to a severe adverse reaction. The administration of an experimental mix of DTPa-HBV and Hib vaccines in a single injection is safe, well-tolerated and immunogenic for all vaccine components.

Immune response to a combined hepatitis B, diphtheria, tetanus and whole-cell pertussis vaccine administered to infants at 2, 4 and 6 months of age.

The objective of this study was to evaluate the immune response and reactogenicity of a combined hepatitis B, diphtheria, tetanus and whole-cell Bordetella pertussis (DTPw-HBV) vaccine administered to healthy infants at 2, 4 and 6 months of age. A total of 179 infants (6-12 weeks of age) received three doses of DTPw-HBV vaccine. Blood samples for antibody determinations were taken before vaccination, 2 months after the second dose and 1 month after the third dose. Solicited and unsolicited symptoms were recorded by parents in a diary card. All vaccinees had protective levels of anti-HBs [geometric mean titre (GMT): 1526 mIU.ml-1], anti-diphtheria and anti-tetanus antibodies, 1 month after the third dose. Ninety-two percent of the subjects exhibited a response to the B. pertussis component. Most (99.4%) solicited reactions occurred within the first 48 h and the majority were mild or moderate. The safety, immunogenicity of this tetravalent vaccine was demonstrated when it was administered in infants following the 0, 2, 4-month dosing schedule.

Safety and immunogenicity of an inactivated hepatitis A vaccine in children 2 to 5 years old.

The reactogenicity and immunogenicity of an inactivated hepatitis A vaccine were assessed. Seventy healthy children aged between 2 and 5 years old, who lacked antibodies against the hepatitis A virus, were enrolled in this study. With a 0-, 1-, and 6-month vaccination schedule, the children received three doses of 360 enzyme-linked immunosorbent assay (ELISA) units of hepatitis A vaccine intramuscularly (deltoid). Safety parameters were recorded in standardized diary cards by the parents on the day of injection and the three following days. Blood tests for liver enzymes and anti-hepatitis A virus antibody analyses were performed the day of screening and 1, 2, 6 and 7 months after the first dose. Anti-hepatitis A virus antibody was tested by ELISA. Titres < 20 mIU/ml were considered negative. For the three hepatitis A vaccine doses administered, 22% (46/210) of the diary cards reported any kinds of signs or symptoms. Soreness at the injection site (9%, 18/210) and malaise (6%, 12/210) were the most common local and systemic reactions reported, respectively. The seroconversion rates were 83, 99 and 100% one month after the 1st, 2nd, and 3rd doses, respectively. The corresponding geometric mean titres were 124, 352, and 2,778 mIU/ml. We conclude that this HAV vaccine is safe and immunogenic in healthy children. As the hepatitis A epidemiology pattern is rapidly changing in our country (and other regions), resulting in an increasing population of susceptible adolescents and young adults, we suggest that the routine vaccination against hepatitis A in pre-school children attending day-care centres should be seriously considered.